A basic aluminium chloride with high chlorine content (basicity 1.85) has been crystallized from a concentrated aqueous solution. Its crystal structure has been determined by X-ray structure analysis. The structure contains (Figure 1) with a Keggintype structure.[2] The latter structure is characterized by a particular resonance shift in its 27 Al-NMR spectrum, even in solutions of basic aluminium chlorides, [3] caused by the tetrahedrally coordinated, central aluminium, which is surrounded by 12 other octahedrally coordinated Al atoms. Various crystalline basic aluminium chlorides have been prepared from solutions by Walter-Levy and Breuil.[4] The crystalline phases were characterized by means of X-ray powder analysis and their thermal decomposition was investigated. The powder diagrams of some of these crystalline phases were unambiguously indexed and the lattice constants were determined. This is also the case for a cubic phase prepared at Dow Chemical Co.[5] However, as far as we are aware, results of crystal structure analyses have hitherto not been reported.In this paper, we report on a structure analysis of the most chlorine-rich of the basic aluminium chlorides described by Walter-Levy and Breuil.[4] [6] These authors obtained the salt as a crystalline precipitate that formed after several days following dilution and storage of concentrated basic aluminium chloride solutions. Suitable monocrystals for our structure analysis were obtained serendipitously, in the course of studies on the colloid structures of basic aluminium chlorides. Colloid solutions with an Al:Cl ratio in
A series of new 3-(arylhydrazono)pentane-2,4-diones (1-6) synthesized from pentane-2,4-dione and diazonium salts of respective anilines using the procedure of Japp-Klingemann are described. Complexes with Cu II and Ni II salts are prepared (7-10, respectively). Spectroscopic properties of these compounds have been studied and X-ray crystal structures of selected hydrazones (3, 4, 6) and of the hydrazone complexes (7-10) are reported. The structures of the uncomplexed hydrazones feature an intramolecular N-H···O interaction to yield a six-membered H-bond ring reflecting preference of the hydrazone tautomeric structure. All the complexes are mononuclear 2:1 (L:M) structures of six-membered 869 chelate type involving N 2 O 2 binding sites that are quadratic arranged but differ in the entire coordination environment dependent on the metal and the ligand substitution including distorted octahedral and quadratic pyramidal coordination geometries in the Cu II complexes 7 and 8 or nearly regular square planar coordination geometry in the Ni II complexes 9 and 10, respectively. In the crystal packings, strong and weak H-bond interactions cause supramolecular network structures.
Seven new hexahelicenes (3−7, 9, 10) containing different functional group substituents have been synthesized and, in three cases (4, 8, 10), optically resolved. Optical rotations were measured and CD spectra are reported. X-ray crystal structures of the helicenes 1, 3, 4, 8, and 9 have been determined, of which 4 represents a 1:1 clathrate with acetone. These show a concerted interplay of C−H···O, C−H···π, and π···π supramolecular interactions in the packings, mostly
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